/*
 * Copyright 2009 Original Author(s)
 * 
 * This file is part of Kommando
 * 
 * Kommando is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * Kommando is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with Kommando.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.kommando.core.catalog;

import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import org.kommando.core.util.Assert;

/**
 * Base {@link CatalogObject} implementation.
 * 
 * @author Peter De Bruycker
 */
public abstract class AbstractCatalogObject implements CatalogObject {

    private Map<Class<?>, Object> extensions = new HashMap<Class<?>, Object>();

    @Override
    public boolean equals(Object obj) {
        if (obj instanceof CatalogObject) {
            CatalogObject other = (CatalogObject) obj;
            return getId().equals(other.getId());
        }

        return false;
    }

    @Override
    public int hashCode() {
        return getId().hashCode();
    }

    @Override
    public <T> T getExtension(Class<T> extensionType) {
        Assert.argumentNotNull("extensionType", extensionType);

        if (extensions.containsKey(extensionType)) {
            return extensionType.cast(extensions.get(extensionType));
        }

        for (Object extension : extensions.values()) {
            if (extensionType.isInstance(extension)) {
                return extensionType.cast(extension);
            }
        }

        return null;
    }

    public <T> void setExtension(Class<T> extensionType, T extension) {
        Assert.argumentNotNull("extensionType", extensionType);

        if (extension == null) {
            extensions.remove(extensionType);
        } else {
            extensions.put(extensionType, extension);
        }
    }

    @Override
    public boolean hasExtension(Class<?> extensionType) {
        Assert.argumentNotNull("extensionType", extensionType);

        if (extensions.containsKey(extensionType)) {
            return true;
        }

        for (Object extension : extensions.values()) {
            if (extensionType.isInstance(extension)) {
                return true;
            }
        }

        return false;
    }

    @Override
    public Map<Class<?>, Object> getExtensions() {
        return Collections.unmodifiableMap(extensions);
    }

}
